Follows the service manual(from JWWebster post) p34, set your washer to Field Service Mode. Select knob position 4 to test the hot water valve/signal and position 5 to test the cold water valve/signal.
According to the service manual p19, the water valve is controlled by a 120VAC solenoid. Use the Field Service Mode to send 120VC to the cold water valve. Confirmed with a voltmeter. IF you don't get the 120V during the cold water valve test, trace it back to the main board. It is most likely the relay malfunction or the driving electronic malfunction.
For someone with electronic repair experience, the relay can be replaced easily without buying a new board.